The critical behavior of ferromagnetic transition is investigated by bulk magnetization measurements for La_0.85Co_1.68As₂ crystal with a ThCr₂Si₂-type structure, grown by using NaAs as a flux, in which the vacancies on the both La and Co sites exist. The critical exponents [$\beta$ = 0.388(3), $\gamma$ = 1.44(2) and $\delta$ = 4.855(9)] with Curie temperature $T_c$ = 99.4 K are obtained, whose self-consistency and reliability are verified by the Widom scaling law and the scaling equation. The critical exponents of ferromagnetic transition occurring in La_0.85Co_1.68As₂ belong to the three-dimensional (3D) Heisenberg model, and suggest that the magnetic interaction decays as $J\left(r\right)\sim r^{-4.975}$ with a short range coupling. These results provide helpful information for understanding the mechanism of ferromagnetism emerging in La_0.85Co_1.68As₂ compound.

通过使用 NaAs 作为通量生长的具有 ThCr ₂ Si ₂型结构的La _0.85 Co _1.68 As ₂晶体的体磁化测量来研究铁磁转变的临界行为，其中 La 和 Co 位点上都存在空位. 临界指数 [$\beta$ = 0.388(3), $\gamma$ = 1.44(2) 和 $\delta$ = 4.855(9)] 居里温度 ${吨}_C$= 99.4 K，其自洽性和可靠性得到了 Widom 标度律和标度方程的验证。La _0.85 Co _1.68 As _{2 中}发生的铁磁转变的临界指数属于三维（3D）海森堡模型，并表明磁相互作用衰减为$J\left(r\right)～r^{-4.975}$带有短程耦合。这些结果为理解 La _0.85 Co _1.68 As ₂化合物中出现的铁磁性机制提供了有用的信息。